Composer's Mosaic, or just Mosaic for short, is a music notation
program from Mark of the Unicorn, later MOTU, developers of the
digital audio workstation software Digital Performer.

Mosaic competed for marketshare against the likes of Finale and the
then-nascent Sibelius, but was eventually discontinued. The last
version released was 1.58.

Quote from Wikipedia:

> Mosaic is a now abandoned software program for producing music
> originally appearing as [Professional Composer][1]. Mark of the
> Unicorn, the company that produced the software, decided to update
> Professional Composer and the result was Mosaic. No media release
> was ever produced by the company about Mosaic's demise and the
> product was dropped. Several factors can be theorized: Sibelius and
> Finale were the competitor notation packages; they were developed
> for both Macintosh and Windows platforms. Mosaic was only available
> for Macintosh computers and thus Sibelius and Finale had far larger
> market opportunities.

DL#1: Folder installation of Mosaic 1.45 (registered). Also included
are some fonts that are necessary to run the application properly.

DL#2: CD-ROM image of Mosaic 1.58. Includes both English and Japanese.
When prompted by the installer, enter the Key Code information found
below:

Registration Information for 1.58
Name: anything
Key Code: CM15-1337-1337-68Q

For the internet browser, see [NCSA Mosaic][2].

Compatibility
Architecture: 68k

Notes:

 1. Download #2's "Composers_Mosaic_CD-ROM.dmg", is a FLAT formatted .dmg archive. Meaning: The ".dmg" suffix in this file's name can be swapped with ".iso", or ".cdr", or even ".toast" if necessary, and it will work or mount OK in other programs and OSs. ?with thanks to Protocol 7 for this hint.

 2. If accessing this .dmg file in a classic Mac OS, the [Virtual CD/DVD Utility][3] will mount this image OK. Also, you can add it's name to an emulator's GUI and access this .dmg that way.

  [1]: http://macintoshgarden.org/apps/professional-composer
  [2]: http://macintoshgarden.org/apps/ncsa-mosaic
  [3]: http://macintoshgarden.org/apps/virtual-dvd-romcd-utility